Single-door clear opening: 34" minimum (36" door leaf)
NKBA 4th ed §1.1 DoorwaysDescription
The clear opening of a single doorway should be a minimum of 34" wide, requiring a 36" wide door leaf. The clear opening of a doorway with multiple leaves should be a minimum of 48" wide. All doorways should be a minimum of 78" high, with a ceiling height over the doorway of at least 80".
Why this exists
34" clear opening accommodates wheelchair / mobility-aid passage. The 36" door leaf gives 34" clear after subtracting the hinge offset + stop frame. This is the universal-design baseline the NKBA 4th ed applies across every room — kitchen, bath, mudroom, laundry, office, bedroom.
Measurements
| Property | Operator | Value | Unit | Note |
|---|---|---|---|---|
singleDoorClearOpening | min | 34 | in | Clear opening for single doorway |
doubleDoorClearOpening | min | 48 | in | Clear opening for multi-leaf doorway |
doorwayHeight | min | 78 | in | Door leaf height |
ceilingOverDoorway | min | 80 | in | Ceiling height over doorway |
Categories
Source
Solver enforcement
Browsable only — the solver does not currently enforce this directive (no spec-level data to check against). This entry exists so the architect personas can cite it in conversation and the user can read what the rule says.
Plan symbols this applies to
These plan symbols invoke this directive when placed on a floor plan. Click any to see where it's drawn and what other rules apply to it.
Related directives
- Bathroom entry doorway · NKBA Bath 1
- Kitchen walkway and work-aisle widths · NKBA Kitchen 6
- Wheelchair-maneuvering clearance at doorways · NKBA 4th ed §1.1 Doorways
- Flush flooring transitions; max 1/4" eased, 1/2" beveled · NKBA 4th ed §1.3 Floor Transitions
- Clear floor space at every activity center: 30-32" × 48-52" · NKBA 4th ed §1.5 Clear Floor Space at Activity Centers
Last reviewed 2026-05-14.